P0299 turbo underboost

[daz_j]

Hi all, my 1st time posting on here, but have read some useful advice in the past so hoping someone can help with this please.

I have a 2008 B6 estate CBAB engine 2.0 TDi 140PS, I’m getting the P0299 turbo underboost fault code. The engine runs normally just after start-up but then quickly backs off to about 75% power, the engine warning light is permanently on. It’s still driveable like this going steady, but just when I need more power (overtaking, steep hills) the glow plug warning light pings on and power drops away further. My local garage have checked things out and concluded "possible turbo fault" - I'm no expert but had kind of sussed that out already! They recommended new turbo required.

I’ve read the advice on here and am tempted to have a go at cleaning the turbo in-situ using the Mr Muscle or similar method. I'd be grateful if someone could point me in the right direction for the definitive instructions to do this please.

Cheers,
Daz.